Degree Type

Dissertation

Date of Award

1984

Degree Name

Doctor of Philosophy

Department

Agronomy

Abstract

Galicia is the region located at the northwestern corner of Spain, whose agriculture is characterized by the small size of the farms. This characteristic has forced an intensive type of agriculture, and today many farms are dedicated to milk production;The objective of this dissertation, which was divided into two parts, was to contribute to the knowledge of the forage quality and productivity of the area;In the first part, several summer crops consisting of corn, sunflower, sudangrass and sorghum x sudangrass were compared at two different locations for four years, and corn, which is the most extensively grown crop in the region, was the most appropriate crop for summer forage production;The second part of this dissertation was dedicated to the comparison of the forage production and quality of several common crop rotations and pastures. The annual crop sequences were corn (monocropped), corn (--->) rye, corn (--->) oats with vetch, and corn (--->) Italian ryegrass. The biannual rotations were corn (--->) Italian ryegrass (12 months) (--->) forage rape and the sequences of prairies (--->) corn and short- and long-term prairies lasting three years. These rotations were tested at four locations during three years. The overall conclusion of the experiment was that total dry matter production increased with increasing cropping intensities. The results clearly demonstrated that intensification provided higher yields and that the introduction of corn in the rotation was the main factor for this production increase. The mean yearly production of the highest yielding rotation was about 20 t/ha of dry matter of good quality forage, in rainfed conditions; however, this value could be easily increased in some locations with summer irrigation;The data and the practical field experience suggested that other techniques such as reduced tillage, fertilization, and the economics of the cropping systems are subjects that need further research.

DOI

https://doi.org/10.31274/rtd-180813-6352

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Jaume Lloveras-Vilamanya

Language

en

Proquest ID

AAI8423723

File Format

application/pdf

File Size

363 pages

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